The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.
The fifth generation (5G) cellular systems aim to improve the throughput by a huge factor (even up to 1000 or more), which presents a multitude of challenges, especially considering the scarcity of spectrum at low frequency bands and the need for supporting a very diverse set of use cases. In order to reach this goal, it is important to exploit the higher frequencies such as millimeter wave frequencies in addition to the more conventional lower frequencies. To meet the demands of 5G systems, a new, globally standardized radio access technology known as New Radio (NR) has been proposed. Due to diverse service requirements imposed by NR, a high level spectral containment in the transmitter is required to isolate transmissions with different numerology (so called mixed numerology scenarios) or asynchronous traffic. This, in turn, necessitates new types of waveform processing solutions for achieving sufficiently high performance.
YLI-KAAKINEN, J. et al. Efficient Fast-Convolution-Based Waveform Processing for 5G Physical Layer. IEEE J. Sel. Areas Commun., June 2017, Vol. 35, No. 6, pages 1309-1326, ISSN 0733-8716. discloses a solution for fast-convolution-based waveform processing for 5G. Specifically, a fast-convolution-based filtered orthogonal frequency division multiplexing (FC-F-OFDM) providing optimized multiplexing of filtered groups of cyclic prefix (CP)-OFDM physical resource blocks (PRBs) in a spectrally well localized manner. The presented subband filtering solution is able to suppress interference leakage between adjacent subbands, thus supporting independent waveform parametrization and different numerologies for different groups of PRBs, as well as asynchronous multiuser operation in uplink.
RENFORS, M. et al. FB-MC and Enhanced OFDM Schemes, Document Number D2.1-Enhanced Multicarrier Techniques for Professional Ad-Hoc and Cell-Based Communications (EMPhAtiC), September 2013. discloses various waveform processing techniques involving filter banks and/or OFDM modulators. Specifically, time-domain windowing for the purpose of sidelobe suppression and fast-convolution based filtering for multirate filters are discussed for application in broadband Professional Mobile Radio (PMR) system development.